Lehman College course GEP 630 with Prof. Johnson (Geo-statistics). Bicycle collisions from August 2011 till February 2014 in Manhattan, sub 59th street mapped with intersection catchment areas. I’m taking my bicycle collision study a bit further this semester; I’ll be bringing this data into SatScan for some spatio-temporal cluster analysis which does not require any population at risk (No one really know how many cyclists there are in NYC). Hoping to push this even further and do some spatial regression analysis and trying to predict the collisions with other variables like Citibike usage data and if there are bike lanes or not. Since the collisions are all aggregated to intersections it made sense to me to create intersection catchment areas or catchment streets. (Collision geocoded by The NYPD Crash Data Band-Aid).
— George E. P. Box
Cardinal directions are one of the basic elements of cartography. I’ve had this scan for a while. It names all the 128 cardinal directions in the Icelandic language. The original belonged to my grandfather and hangs in the family summerhouse back in Iceland. It seems that finally I might have to digitize this and create a proper vector graphic version. Perhaps this will be my contribution to safeguard the Icelandic language maybe. But having 128 words to choose from when pointing at something is far from practical, but it’s cool right?
Lehman College course GEP 630 with Prof. Yuri Gorokhovich (Natural Hazards and Disasters). The goal of this nifty little exercise was to estimate the impact of a 10 meter Tsunami near JFK airport. No instructions given, just data.
Lehman College course GEP 630 with Prof. Johnson (Geo-statistics). The 3 maps show rates mapped to the to the ZIP code level. The first one uses the raw rates but the second and the third use two different types of parametric smoothing called Empirical Bayes (EB), a global version and a local version. Note that although all the maps show rates classified into 5 classes (natural breaks) the values for each class are not the same when the maps are compared.
Icelandic police officers doing some accident cluster analysis in 1968. (original image).
I’ve been thinking a lot about GIS teaching methods lately and how powerful a simple image (or a map) can be. Here’s my very simple stab at explaining a digital elevation model (DEM) represented as a raster, how the elevation is stored in a single cell and how we might think of it in 3D. Only a draft and would presented with minimal text for clarification. Data from The National Land Survey of Iceland.
Experimenting with a couple of things in ArcGIS like batch processing scripts and model shadows for the hillshade tool (and the Tumblr gif size limit!). Higher latitudes experience dramatic change in sunlight over a course of one year. This hillshade animations show sunlight for 21 June (summer solstice) in 2013 for the town of Isafjordur in Iceland located just north of 66°N on the spit in a fjord near the middle of the map. For some, there is no sunset. Ragnar Thrastarson - Lehman College GISc Program. Data: www.lmi.is/en